redhat-talk-cron_strangeness_in_rh8

This is part of The Pile, a partial archive of some open source mailing lists and newsgroups.



To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: Cron strangeness
Date: Mon, 28 Apr 2003 14:19:21 -0400

Last week, my Red Hat 8.0 system quit executing scheduled cron jobs.  It had
been running the jobs reliably for months prior, but just quit.  The
/var/log/cron file shows all the jobs being run as if nothing were wrong,
but the jobs don't actually run, nor do they generate email to root as they
had before.  As a test, I created a simple script that sends a text file to
root via email, and scheduled it to run every minute.  The /var/log/cron
file shows an entry for every minute, but no email was sent.

Anybody know what's going on here?


===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 15:18:15 -0400


Roger [mailto:roger@efn.org] wrote:

> have you tried running the jobs from the command line?

Yes.  All these jobs have run reliably, either by cron or from the command
line, for months prior.
===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 15:25:27 -0400

Jeff McKeon [mailto:jsm@inpro.net] wrote:

> Did you make any permissions changes on the jobs?

There may have been, however cron executes them as root.  Could permission
changes cause this even though they are executed as root?

===

To: Redhat list <redhat-list@redhat.com>
From: Peter Peltonen <peter.peltonen@fivetec.com>
Subject: Re: Cron strangeness
Date: 28 Apr 2003 22:34:41 +0300

Roger wrote:

> >had before.  As a test, I created a simple script that sends a text file to
> >root via email, and scheduled it to run every minute.  The /var/log/cron
> >file shows an entry for every minute, but no email was sent.

Is sendmail running? Can you send other email from the system normally?
What else is the system trying to do than send an email?

===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 15:57:23 -0400

Info - Demerson [mailto:demerson@zaffari.com.br] wrote:

> Maybe the cron has stopped... 
> try service anacron status 

I have rebooted the machine and looked at DMESG for any strangeness.  Heres
what happens when I try 'service anacron status':

# service anacron status
anacron dead but subsys locked

===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 15:58:55 -0400

Peter Peltonen [mailto:peter.peltonen@fivetec.com] wrote: 

> Is sendmail running? Can you send other email from the system normally?
> What else is the system trying to do than send an email?

I can run the script manually.  It sends mail.  The other scripts do data
transfers via FTP from several different systems, and run SQL code to import
into MYSQL.

===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Peter Peltonen <peter.peltonen@fivetec.com>
Subject: RE: Cron strangeness
Date: 28 Apr 2003 23:20:17 +0300

Jim Moseby wrote:

> I have rebooted the machine and looked at DMESG for any strangeness.  Heres
> what happens when I try 'service anacron status':
> 
> # service anacron status
> anacron dead but subsys locked

It seems that your anacron has died abnormally. It keeps a lock file at 
/var/lock/subsys directory. A lock file is a file which the system can query
to see if a process is alive (if the file exists -> process alive). 

Sometimes when process dies abnormally the lock file is not removed and
you need to remove it by hand to get the process started again (the
startup scripts usually query it to see if the process is already
running). So do:

  root# rm /var/lock/subsys/anacron
  
  root# service anacron start

===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 16:28:11 -0400

Thanks.  I did what you suggested, and the following occured:


# service anacron status
anacron dead but subsys locked
# ls /var/lock/subsys/a*
anacron  apmd  apache  atd
# rm -f /var/lock/subsys/anacron
# service anacron start
Starting anacron:                                          [  OK  ]
# service anacron status
anacron dead but subsys locked
# ps ax |grep anacron
#

It says it started, but there is no anacron in the 'ps ax' list, and
'status' still says anacron is dead.  Any ideas?

Jim

-----Original Message-----
From: Peter Peltonen [mailto:peter.peltonen@fivetec.com]
Sent: Monday, April 28, 2003 4:20 PM
To: 'redhat-list@redhat.com'
Subject: RE: Cron strangeness


On Mon, 2003-04-28 at 22:57, Jim Moseby wrote:
> I have rebooted the machine and looked at DMESG for any strangeness.
Heres
> what happens when I try 'service anacron status':
> 
> # service anacron status
> anacron dead but subsys locked

It seems that your anacron has died abnormally. It keeps a lock file at 
/var/lock/subsys directory. A lock file is a file which the system can query
to see if a process is alive (if the file exists -> process alive). 

Sometimes when process dies abnormally the lock file is not removed and
you need to remove it by hand to get the process started again (the
startup scripts usually query it to see if the process is already
running). So do:

  root# rm /var/lock/subsys/anacron
  
  root# service anacron start

===

To: redhat-list@redhat.com
From: tony@pfeiffer.edu via thanatos.pfeiffer.edu
Subject: Re: Cron strangeness
Date: Mon, 28 Apr 2003 17:03:33 -0400 (EDT)

Peter mentioned sendmail below. Has anyone else noticed that somehwere in
the last couple distro releases ie, 7.3, 8 and 9, that sendmail must be
running all the time in order for cron jobs to be sent?

In other words, I have to run

chkconfig --list sendmail

to make sure its starting on those servers, just so I can send nightly 
cron job results. If anyone knows of a better solution, that would be 
excellent.

As far as the problem with cron jobs not sending, I think that's the 
answer -- fire up sendmail with its init script. my .02 anyway

===

To: redhat-list@redhat.com
From: Andrew Williams <andrew.williams@sourcefire.com>
Subject: Re: Cron strangeness
Date: 28 Apr 2003 17:15:55 -0400

On Mon, 2003-04-28 at 17:03, Tony Inskeep wrote:
> Peter mentioned sendmail below. Has anyone else noticed that somehwere in
> the last couple distro releases ie, 7.3, 8 and 9, that sendmail must be
> running all the time in order for cron jobs to be sent?
> 
> In other words, I have to run
> 
> chkconfig --list sendmail
> 
> to make sure its starting on those servers, just so I can send nightly 
> cron job results. If anyone knows of a better solution, that would be 
> excellent.

You can use Net::SMTP to send data sent over STDIN to someone via a
specified mailserver.  Should be a quick 5 or 6 liner.

===

To: redhat-list@redhat.com
From: Robert Jones <kerplop@ectisp.net>
Subject: Re: Cron strangeness
Date: Mon, 28 Apr 2003 17:42:58 -0500

As I read through several responses to this question, I started wondering 
how the discussion turned to ANACRON. Referring to the original post 
(below) I still don't know how anacron became involved.


On Monday 28 April 2003 02:37 pm, redhat-list-request@redhat.com wrote:
> From: Jim Moseby <JMoseby@nrbindustries.com>
> To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
> Subject: Cron strangeness
> Date: Mon, 28 Apr 2003 14:19:21 -0400
> Reply-To: redhat-list@redhat.com
>
>
> Last week, my Red Hat 8.0 system quit executing scheduled cron jobs.
>  It had been running the jobs reliably for months prior, but just
> quit.  The /var/log/cron file shows all the jobs being run as if
> nothing were wrong, but the jobs don't actually run, nor do they
> generate email to root as they had before.  As a test, I created a
> simple script that sends a text file to root via email, and scheduled
> it to run every minute.  The /var/log/cron file shows an entry for
> every minute, but no email was sent.

Frankly, I don't know what's going on with cron but if I look at anacron, 
I get the same result as someone noted:
[rj@blackhole nsmail]$ /sbin/service anacron status
anacron dead but subsys locked
...and my cron jobs are executing as they should.

Maybe the OP should try checking the cron daemon
[rj@blackhole nsmail]$ /sbin/service crond status
crond (pid 2093) is running...
...restarting that baby if nothing else works.


===

To: "'Robert Jones '" <kerplop@ectisp.net>,
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 23:05:31 -0400

Interestingly, a previous poster, whom I had assumed didn't get the gist of
the problem, asked "Is sendmail started?"  It wasn't.  But I didn't think
that had anything to do with the problem - cron jobs not executing.

I started sendmail, and all of a sudden, cron jobs are working again.  :o/

Now that the immediate problem is fixed, the questions become

1. "Why does cron require sendmail to be running?"
2. "If cron does require sendmail, why doesn't it complain if it's not
running?"
3. "If cron does not require sendmail, why did starting sendmail fix this
problem?

Hmmmmmmm

Now I'm going to go RTFM and see if it says anything about requiring
sendmail.   Thanks to all who replied, especially the one who asked if
sendmail was started.  :o)

===

To: redhat-list@redhat.com
From: Bret Hughes <bhughes@elevating.com>
Subject: RE: Cron strangeness
Date: Mon, 28 Apr 2003 23:15:10 -0500

On Mon, 2003-04-28 at 22:05, Jim Moseby wrote:
> Interestingly, a previous poster, whom I had assumed didn't get the gist of
> the problem, asked "Is sendmail started?"  It wasn't.  But I didn't think
> that had anything to do with the problem - cron jobs not executing.
> 
> I started sendmail, and all of a sudden, cron jobs are working again.  :o/
> 
> Now that the immediate problem is fixed, the questions become
> 
> 1. "Why does cron require sendmail to be running?"
> 2. "If cron does require sendmail, why doesn't it complain if it's not
> running?"
> 3. "If cron does not require sendmail, why did starting sendmail fix this
> problem?
> 
> Hmmmmmmm
> 
> Now I'm going to go RTFM and see if it says anything about requiring
> sendmail.   Thanks to all who replied, especially the one who asked if
> sendmail was started.  :o)
> 

I think the jobs were running you just weren't getting the cron
generated emails.  Did you get all the old ones too?

===

To: redhat-list@redhat.com
From: Beast <beast@setuid.com>
Subject: Re: Cron strangeness
Date: Tue, 29 Apr 2003 12:18:52 +0700

Tuesday, April 29, 2003, 10:05:31 AM, Jim wrote:

> Interestingly, a previous poster, whom I had assumed didn't get the gist of
> the problem, asked "Is sendmail started?"  It wasn't.  But I didn't think
> that had anything to do with the problem - cron jobs not executing.

> I started sendmail, and all of a sudden, cron jobs are working again.  :o/

> Now that the immediate problem is fixed, the questions become

> 1. "Why does cron require sendmail to be running?"

not cron, but your job.

> 2. "If cron does require sendmail, why doesn't it complain if it's not
> running?"

cron doesn't know anything about jobs.
cron doesn't know that your job is require sendmail to run.

> 3. "If cron does not require sendmail, why did starting sendmail fix this
> problem?


===

To: redhat-list@redhat.com
From: "Mike Vanecek" <rh_list@mm-vanecek.cc>
Subject: RE: Cron strangeness
Date: Tue, 29 Apr 2003 00:33:29 -0600

Jim Moseby <JMoseby@nrbindustries.com> wrote:

> Yes.  All these jobs have run reliably, either by cron or from the command
> line, for months prior.

Could it be that cron starts and then abends due to an error in one of the
cron scripts? Maybe you should try running each of the cron scripts from the
command line and see if any of them crash. Any changes made to /etc/crontab
that could have inserted an error which causes cron to stop. That they have
run reliably for months is not material; something is causing them not to run.
Process your cron configuration manually as though you were the system. As you
walk through, something should not be working correctly. For example, one of
the first things that cron does is run anacron. If that is abending, could it
be that error stops any further processing by cron?

===

To: redhat-list@redhat.com
From: Ritesh Raj Sarraf <rrs_rhlist@softhome.net>
Subject: Re: Cron strangeness
Date: 29 Apr 2003 12:45:37 +0530

On Mon, 2003-04-28 at 23:49, Jim Moseby wrote:
> Last week, my Red Hat 8.0 system quit executing scheduled cron jobs.  It had
> been running the jobs reliably for months prior, but just quit.  The
> /var/log/cron file shows all the jobs being run as if nothing were wrong,
> but the jobs don't actually run, nor do they generate email to root as they
> had before.  As a test, I created a simple script that sends a text file to
> root via email, and scheduled it to run every minute.  The /var/log/cron
> file shows an entry for every minute, but no email was sent.
> 
> Anybody know what's going on here?

is sendmail running on the localport 127.0.0.1
if not enable it.


===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Tue, 29 Apr 2003 07:58:40 -0400

Mike - Running the scripts manually is exactly what I have had to do since
cron stopped working.  They all run without error.  

===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Tue, 29 Apr 2003 08:01:19 -0400

Mr. Beast,

None of my jobs require sendmail.  Cron (by default) sends any output the
jobs generate to root.  The jobs not running was the problem, the missing
mail was a side-effect.

Thanks for playing...


===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness
Date: Tue, 29 Apr 2003 08:04:32 -0400

Nope.  The jobs weren't running.  This machine is a data warehouse.  It
gathers data from several disparate systems by way of these scripts, and
each script keeps a log of its activitiy.  They definately weren't running
until I started sendmail yesterday.

Thanks!

JM

PS - No, I didn't get any backlogged emails when I started sendmail.


===

To: "'redhat-list@redhat.com'" <redhat-list@redhat.com>
From: Jim Moseby <JMoseby@nrbindustries.com>
Subject: RE: Cron strangeness 
Date: Tue, 29 Apr 2003 08:22:25 -0400

A new twist -  This morning I decided to stop sendmail and see if the cron
jobs stop as well.  They don't.  Cron jobs execute fine now whether or not
sendmail is started.  (Just no email without sendmail) :o/

So, we fixed the problem yesterday some other way, and starting sendmail was
a coincidence.  Maybe stopping crond and anacron, deleting the corresponding
/var/lock/ entries, and restarting them did the trick. (?)

Anyway, problem solved, tragedy averted, thanks for yor time.


===

To: redhat-list@redhat.com
From: Bret Hughes <bhughes@elevating.com>
Subject: RE: Cron strangeness
Date: 29 Apr 2003 08:40:37 -0500

On Tue, 2003-04-29 at 07:04, Jim Moseby wrote:
> Nope.  The jobs weren't running.  This machine is a data warehouse.  It
> gathers data from several disparate systems by way of these scripts, and
> each script keeps a log of its activitiy.  They definately weren't running
> until I started sendmail yesterday.
> 
> Thanks!
> 
> JM
> 
> PS - No, I didn't get any backlogged emails when I started sendmail.
> 

You know if you can replicate this, it is a good idea to file a bug
report.  I think I bumped into this helping my brother on a 8.0 system
that was not sending cron related mail.  I this case there were 50 or so
mails that got sent once I started sendmail. 


===


the rest of The Pile (a partial mailing list archive)

doom@kzsu.stanford.edu